Johnson has been dealing with a knee injury for the past three weeks, but this is the first time he’s missed an entire week of practice because of it.

Receiver Calvin Johnson hasn’t missed an NFL game since Week 17 of the 2010 season, when a bad ankle prevented him from playing in a Lions victory over the Vikings.

Johnson missed his third straight day of practice Friday with a knee injury and is officially listed as questionable for Sunday’s game at Jacksonville.

“He’s done it before,” Lions head coach Jim Schwartz said of Johnson not practicing during the week and still playing on Sunday. “He obviously knows our offense, and then his health is the most important thing.”

Johnson has been dealing with a knee injury for the past three weeks, but this is the first time he’s missed an entire week of practice because of it.

“Any time your players aren’t out there it’s definitely a concern,” Schwartz said. “An ideal situation is to go practice every day, but by the time you get to the middle of a NFL season, nothing’s ideal.”

The Lions are trying to get back to .500 with a victory in Jacksonville and would certainly like to have their leading receiver to help accomplish that early-season benchmark. Johnson has 41 receptions for 638 yards and a touchdown.

“That's the main thing, just being ready for Sunday," Johnson said on Thursday. "I have to be out there to help these guys out."

Even if Johnson isn’t 100 percent, his mere presence on the field is a key component of the Lions offense. His impact goes way beyond just catching the football.

Johnson had a hand in all three of the Lions’ touchdown receptions in last week’s victory over Seattle, even though he didn’t actually catch any of them himself. In all three instances the coverage rolled over to Johnson, leaving one-on-one situations for Titus Young (2) and Ryan Broyles to take advantage of.

Even if Johnson isn't 100 percent, him being on the field give the Lions the best decoy in all of football.

DELMAS' RECOVERYWhen safety Louis Delmas was dealing with a sore knee in training camp (that ultimately needed surgery), Lions defensive coordinator Gunther Cunningham said he knew it was bad because of Delmas' demeanor.

“He’s one of the finest young men I’ve been around,” Cunningham said. “He makes me laugh every day. In his first injury this year, he was really moody and wouldn’t talk much.”

Cunningham said it’s been different this time around after Delmas hurt the same knee against Seattle last week.

“What happened this time is a little bit different. The other day we had it out in a team meeting, a defensive team meeting, and he was laughing, which tells me a lot,” he said. “It means that he’s going to be back soon and the thing’s healing. So, I’m excited for him about that.”

That's not exactly a scientific approach to diagnosing recovery time, but Lions head coach Jim Schwartz also said Delmas is day-to-day. He’s already been ruled out for Sunday’s game at Jacksonville, though.

The Lions play at Minnesota next week and it seems Cunningham is hopeful he can play then.